pancuronium and Heart-Diseases

Topics: Adjuvants, Anesthesia; Aged; Analgesics, Opioid; Anesthesia; Anesthetics, Intravenous; Angina, Unstable; Bartter Syndrome; Cardiopulmonary Bypass; Catheterization, Swan-Ganz; Coronary Artery Bypass; Female; Fentanyl; Heart Diseases; Humans; Intubation, Intratracheal; Isotonic Solutions; Monitoring, Intraoperative; Morphine; Neuromuscular Nondepolarizing Agents; Pancuronium; Propofol; Ringer's Solution; Scopolamine

We have studied the effect of non-depolarizing neuromuscular blocking agents, at concentrations present in serum during anaesthesia, on release of [3H]-norepinephrine ([3H]NE) from superfused atrial appendage obtained during cardiac surgery from 48 patients. Three of the neuromuscular blocking agents (pancuronium, gallamine and rocuronium), which are known to cause an increase in heart rate during anaesthesia, increased stimulation-evoked release of [3H]NE. In contrast, (+)tubocurarine and pipecuronium, neuromuscular blocking agents that do not cause tachycardia, did not affect release of NE. Org 9487 significantly enhanced release while SZ1677 was ineffective, even at concentrations higher than those expected after administration of a 2 x ED95 dose. Atropine enhanced release. These data suggest that the axon terminals of sympathetic nerves in human heart have muscarinic heteroreceptors whose activation by acetylcholine (ACh) released from the vagal nerve reduces release of NE. This action contributes to lowering of heart rate. Therefore, any neuromuscular blocking agent with antimuscarinic actions and capable of increasing the release of NE may produce tachycardia.

Topics: Analysis of Variance; Androstanols; Atropine; Electric Stimulation; Gallamine Triethiodide; Heart Atria; Heart Diseases; Heart Rate; Humans; Myocardium; Neuromuscular Blocking Agents; Neuromuscular Depolarizing Agents; Neuromuscular Nondepolarizing Agents; Norepinephrine; Pancuronium; Pipecuronium; Rocuronium; Tubocurarine; Vecuronium Bromide

We studied 20 adult patients undergoing cardiac surgery. All received pancuronium as the sole neuromuscular blocking drug and no reversal agent was used. In the postoperative intensive care unit, mechanical ventilation was continued and patients were sedated with an infusion of propofol. Neuromuscular block was measured electromyographically at appropriate intervals until the train-of-four ratio (TOF) reached 0.8. At the time when the propofol infusion would normally be discontinued, 13 patients (65%) demonstrated a TOF of less than 0.8 (group median 0.23, interquartile range 0.11-0.6). Subsequently, the median time to achieve a TOF of 0.8 was 2 h 10 min (interquartile range 1 h-2 h 25 min). We found that if pancuronium was used during cardiac surgery, a significant proportion of patients remained partially paralysed when they would normally be allowed to emerge from anaesthesia in the ICU.

Topics: Aged; Anesthesia Recovery Period; Critical Care; Electromyography; Female; Heart Diseases; Humans; Male; Middle Aged; Neuromuscular Blockade; Neuromuscular Nondepolarizing Agents; Pancuronium

Topics: Adult; Anesthesia, General; Anesthetics; Blood Pressure; Diazepam; Electrocardiography; Extracorporeal Circulation; Heart Diseases; Heart Rate; Humans; Intubation, Intratracheal; Ketones; Middle Aged; Nitrous Oxide; Oxygen; Pancuronium; Phenoperidine; Pregnanes